1. Field of the Invention
The present disclosure relates to a suction brush for a vacuum cleaner. More particularly, the present disclosure relates to a suction brush for a vacuum cleaner capable of automatically controlling a gap between a lower casing provided with a suction port and a surface to be cleaned according to whether the surface to be cleaned is a hard floor or a carpet.
2. Description of the Related Art
Generally, vacuum cleaners are electric appliances that draw in and collect contaminants from a surface to be cleaned using a suction force generated by a vacuum generator. Various types of vacuum cleaners have been developed and used. A canister type vacuum cleaner generally includes a main body, a connection part, and a suction brush.
The vacuum generator such as a suction motor generating the suction force and a contaminants collecting part in which the drawn in contaminants are collected are disposed in the main body. The connection part includes a handle grasped by a user, an extension pipe connecting the handle and the suction brush, and a flexible hose connecting the handle and the main body. Also, the suction port is formed on a bottom surface of the suction brush so that the suction brush can draw in contaminants from the surface to be cleaned through the suction port.
The vacuum cleaner may be used to clean the surface to be cleaned such as a hard floor, and a carpet. Here, the hard floor refers to surfaces to be cleaned having a smooth surface such as, but not limited to, those formed of stone, wood, and linoleum.
When cleaning the hard floor, the suction brush of the vacuum cleaner is often stuck to the surface to be cleaned. When the suction brush is stuck to the surface to be cleaned, a handling resistance of the suction brush is increased. So a user is required to apply a greater force to handle the suction brush. When cleaning the surface to be cleaned like the carpet, the suction brush is stuck to the carpet less often than the hard floor. However, when cleaning the carpet, the vacuum cleaner needs to use the suction force greater than that used for cleaning the hard floor in order to draw in contaminants among tight wool or fibers (herein after “wool”) of the carpet.
The handing resistance and suction force of the suction brush with respect to the surface to be cleaned are closely related to a gap between the surface to be cleaned and the bottom surface of the suction brush on which the suction port is formed. That is, as the gap between the surface to be cleaned and the bottom surface of the suction brush decreases, the handling resistance and suction force increase. As the gap between the surface to be cleaned and the bottom surface of the suction brush increases, the handling resistance and suction force decrease.
Therefore, in the case of the suction brush constantly maintaining the gap between the surface to be cleaned and the bottom surface of the suction brush, when cleaning the hard floor, the handling resistance is increased so that a user is required to use a lot of force to handle the suction brush. Also, when cleaning the carpet, the suction force is weak so that the suction brush cannot effectively draw in contaminants between wool of the carpet.
To solve the problem, suction brushes that can adjust the gap between the surface to be cleaned and the bottom surface of the suction brush according to types of the surfaces to be cleaned have been developed. The suction brushes have a lever projecting from a top surface thereof to be manually handled by a user. Therefore, when cleaning the hard floor, the user controls the lever to increase the gap between the surface to be cleaned and the bottom surface of the suction brush, thereby reducing the handling resistance. When cleaning the carpet, the user controls the lever to decrease the gap between the surface to be cleaned and the bottom surface of the suction brush, thereby increasing the suction force.
However, because the suction brush is configured so that the user manually controls the lever to adjust the gap between the bottom surface of the suction brush and the surface to be cleaned, whenever the type of the surface to be cleaned changes, the user should manually control the lever. As a result, the use of the vacuum cleaner may feel onerous.